<template>
  <div>
    <table 
    border="1" 
    width="700" 
    style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="isAll"/> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <tr v-for="(obj, index) in goodList" :key="index">
          <th><input type="checkbox" v-model="obj.checked"/> <span></span></th>
          <th>{{ obj.name }}</th>
          <th>{{ obj.price }}</th>
          <th>
            <button @click="add(index)">+</button>
            <span>{{ obj.num }}</span>
            <button @click="sec(index)">-</button>
          </th>
          <th>{{ obj.price * obj.num }}</th>
          <th><button @click="out(index)">删除</button></th>
        </tr>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:{{ allPrice }}</td>
          <td colspan="5"></td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>
<script>
export default {
  data() {
    return {
      goodList: [
        {
          name: "诸葛亮",
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: "蔡文姬",
          price: 1500,
          num: 1,
          checked: false,
        },
        {
          name: "妲己",
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: "鲁班",
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
    };
  },
  methods: {
    add(index) {
      this.goodList[index].num++;
    },
    sec(index) {
      if (this.goodList[index].num !== 0) {
        this.goodList[index].num--;
      }
    },
    out(index) {
      this.goodList.splice(index, 1);
    },
  },
  computed: {
    allPrice() {
      return this.goodList.reduce((sum, obj) => {
        return (sum += obj.price * obj.num);
      }, 0);
    },
    isAll:{
        set(val){
        // console.log(val);
       return this.goodList.forEach(obj=>obj.checked = val)
      },
      get() {
       return this.goodList.every(obj=>obj.checked === true)
      }
    }
  },
};
</script>
<style>
</style>